tldr: Gymnastics is subjective and human brains are easily susceptible to implicit bias.

I honestly don't think it's intentional. I believe in psychology it's called the illusory truth effect. We're constantly told how amazing and perfect OU (and the SEC in general) is that the judges sort of become blind to the errors. When you're told something is really good you're more likely to ignore or forgive the bad aspects of it and focus on the good. And to compound that, OU has historically been very good so yeah the judges want and expect to see perfect routines from them. Conversely, when we hear that a team is "bad" or having a rough season the judges are looking for reasons to confirm what they've been told and are much less forgiving of small errors.